Electrically actuated heat motor



Jan. 27, 1942. I. E. M CABE ELECTRICALLY ACTUATED HEAT MOTOR Filed Feb.27, 1939 r0 mn/fi z'l/lldzzz 52 r17 4 2 W ar 7 M M M I 3 W T v 4 Vi N 3N m "m E 0 m m M Patented Jan. 27, 1942 UNITED STATES PATENT OFFICEELECTRIC-ALLY acruaran niza'r MOTOR Ira E. McCabe, Chicago, Ill.

Application February 27, 1939, Serial No. 258,591

Claims.

' larly to a motor of this type which may be substituted for aself-starting synchronous electric motor.

It is an object of this invention to employ one or more thermal membersof bi-metallic metal which will expand and contract in response to thepresence or absence of heat to impart movement to a driven member incombination with an electric resistance heater actuated by the movementof the thermal member to reciprocate the electrical heater toward andaway from said member. It is a further object of this invention toemploy two co-acting thermal members to be alternately subjected to thepresence of heat and to transmit the cooling and heating movements ofthe two thermal elements through a transmission mechanism to the drivingshaft of the heat motor.

One of the advantages of such a construction is that by providing twothermal members, the effect of ambient temperature is nullified and doesnot effect the operation of the heat motor. Another advantage is that asingle heating element may be employed to actuate a plurality of thermalmembers. Another advantage is that the movement of the thermal membersin response to the heating element is transmitted to automaticallyreciprocate a single heating element between the adjacent thermalmembers which simplifies the construction and eliminates the necessityof providing electrical contacts and switching apparatus, the operationof which would create interference with radio reception.

With these and other objects in view, reference is made to theaccompanying sheet of drawings which illustrates aggreferred form ofthis invention, with the understanding that detail changes may be madewithout departing from the scope thereof.

In the drawing:

Figure 1 is a view in front elevation of a heat motor constructed inaccordance with this invention, with parts broken away and detached fromthe base or supporting plate.

Figure 2 is a view in side elevation of Figure 1 In the embodiment ofthis invention, as illustrated in Figures 1, 2 and 3, cylindricalsections l and 2 of bi-metallic metal are each provided with are-entrant portion at one end, each of which is mounted upon oppositelydisposed angular end portions of brackets 3 and 4, respectively, saidbrackets mounted upon the upper portion of a base plate B so that thecenters of the respective cylindrical sections lie in the samehorizontal plane with their respective adjacent peripheries spaced apartfrom each other. A floating operating link 5 is provided with an upwardprojection 6 at one end terminating in an angular extension I which ispassed through a slot provided therefor in the free end of thecylindrical section I and the opposite end of the link 5 is providedwith an upward projection 8 adapted to be connected by a hinge 9 to thefree end of the cylindrical section 2. The two projections I and 8 areso connected and arranged as to support the link 5 in a horizontalposition. The link 5 is provided with a depending portion l0 extendingbelow the projection 8, the lower extremity of which supports a heateractuator l l pivoted at one end to the portion ill. The free end of theactuator ll mounts a roller l2 and is normally urged in an upwarddirection by the spring l3, one end of which engages the actuator Iiwith the other end anchored upon the portion ill of the link 5. Theroller l2 co-acts with an oscillator ll carried upon an enlarged portionl5 of a shaft l6 mounted in a bearing therefor in the back plate B. Anoscillating heater support plate I! of insulating material is secured tothe enlarged portion l5, which plate is provided with terminal posts l8and I9 upon the upper side thereof. A fiat rectangular electricresistance heater 20 with its flat surface P sitioned parallel to thesurfaces of the cylindrical sections l and 2 is supported between theadjacent surfaces thereof by electrical conductors 2| and 22 connectedto the opposite ends of the resistance wire 23 of the. heater 20. Theelectrical conductors are preferably covered with insulation and theirlower respective ends are connected to the terminal posts It and it uponthe insulated heater actuator plate ll.

The outer end of the shaft I6 is mounted in a bearing therefor in ahorizontal front plate 24 spaced apart from the base plate B by studs 25to lie parallel therewith, as shown in Figures 2 and 3, so that theshaft l6 may be oscillated in the said bearings.

The oscillator I4 is preferably in the form of threaded pin 28terminating in a conical end received in the enlarged portion l of theshaft l3 to provide for adjustment. The upper end of the pin 23 isprovided with a knurled head 21 adapted to be engaged and locked in thead- .iusted position by the free end of a spring 23 secured to the outerend of the enlarged portion Ii of the shaft It. The lower conical end ofthe actuator I4 is adjusted so that the roller [2 of the actuator IIwill normally engage one conical surface thereof and oscillate the shaftII and plate I! to cause the heater to engage the adjacent surface ofone of the cylindrical bi-metallic sections of the thermal members. Theterminal posts l8 and I! pass through the plate I! of insulatingmaterial and are connected to a source of electricity by conductors 29.When the current passes from the source through con: nectors 29,terminal posts i8 and i9, conductors 2| and 22 and resistance wire 23 ofthe heater Ill, and the heater is in the position shown in Figure 1, itwill cause the adjacent cylindrical section I of the thermal member toreduce in cylindrical form, thus moving the free end downwardly andinwardly, which will cause the floating lever 5 to be rotated about itshinge connection 3 with the other thermal member 2 and thereby cause theheat actuator II to move toward the right causing the roller 12 totravel down the conical termination of the oscillator pin 23 to rideover the apex thereof. The tension of the spring l3 as the roller ridesover the apex will cause the roller to travel upwardly over the oppositeconical side of the pin 26 which will impart a rotation to the shaft i6causing the heater support plate ll to oscillate the heater 23 and bringit into contact with the thermal member 2. When the heater 23 contactsthe adjacent surface of the thermal member 2, the thermal member 2 willbe heated to impart a reverse movement to the floating link 5 to causethe actuator II to travel in the opposite direction over the conicalsurface and apex of the oscillator i4 to impart a reverse oscillation tothe heater 20. With the alternate heating of the thermal members onemember when heated will be assisted by the other member while coolingwhereby the combined moving force of both elements is applied to thefloating lever 5 in moving it and an oscillating movement will beimparted to the heater 20 through the reciprocal movement of thefloating link 5 as long as the resistance element 23 of the heater 2!)is energized.

The floating link 5 is provided with two spaced apart depending similaroperating members 30 and 3! adapted to receive in sliding engagementbetween them a stud 32 carried upon a reciprocating cradle 33. Theopposite ends of the cradle 33 are pivotally mounted upon shafts 34 and35, each of which shafts are supported by a pair of links 33 and 31, thelower ends of which are pivotally mounted upon studs 33 and 33, mountedbetween the base plate B and front plate 24; each pair of links beingconnected lntermediate their length by spacing members 40. By thisconstruction, when the oscillating heater causes the thermal members iand 2 to impart an oscillating movement to the floating link 5, thismovement through the operating members 33 and 3| will transmit areciprocating movement to the cradle 33.

A shaft 4| is received within a hub, mounted upon a ratchet wheel 43 inany desired manner to be rotatable therewith. The ratchet wheel 43 islocated between the base plate 13 and cradle 33 with the hub passingthrough a bearing 42 provided therefor in the base plate. Thereciprocating movement of the cradle 33 is transmitted to the ratchetwheel 43 to impart a rotation to the shaft 4| by pawls 44 in the form offlat springs each having slots 45 adjacent their free end adapted tocause the body of the spring adjacent the free end to form a pawl toengage the ratchet teeth of the ratchet wheel 43 on opposite sides ofthe shaft 4|. The end of the upper spring pawl 44 opposite the slot 45is secured to the upper end of a portion 45 of the cradle 33 extendingupwardly therefrom above the pivot 35 and the corresponding portion ofthe lower spring pawl 44 is secured to a portion 41 of the cradle 33depending below the pivot 34 and cut out to provide clearance for thespacer 40.

By this arrangement, the pawls 44 are always in engagement with theteeth of the ratchet wheel 43. Movement of the cradle to the rightimparts a clockwise rotation to the ratchet wheel by the upper pawl 44while movement of the cradle 33 to the left continues the clockwiserotation of the ratchet wheel by the movement of the lower pawl 44.While one pawl imparts movement to the ratchet wheel the other pawltravels over the ratchet teeth.

By providing the ratchet wheel 43 with fine teeth and synchronizing themovement of the elements I and 2, a continuous or substantiallycontinuous rotation may be imparted to the shaft 4!. In order tosynchronize the movements of the free ends of the elements I and 2, itis preferable to provide an adjustment for one of the elements. As shownin Figure 1, the bracket 4 is made adjustable so that the thermalelement 2 may be adjusted in a vertical direction. The bracket 4 isprovided with a right angular extension 48 which receives an adjustingscrew 49 mounted in a bracket 50 secured to the base plate B. Thebracket 4 is also provided with a vertical slot through which a clampscrew 5| passes and by means of which the bracket may be secured inposition after adjustment. Should the movement of the two thermalelements differ slightly when heated, the element 2 may be raised orlowered to adjust the relationship of the heater actuator roller I2 tothe oscillator l4 for each element. Therefore, the heating effect of theheater on each element may be timed to cause each element, when heated,to apply the same degree of rotation to the ratchet wheel 43 and sincethe oscillator 14 is adjustable the heating periods may be determined toregulate the number of degree rotation which may be imparted by thethermal members for each cycle of operation thus providing a certaindesired rotation of the wheel 43 over a desired period of time.

While this application of the heat or electrothermal motor is describedin connection with the timing mechanism disclosed in said Patent No.2,139,454 as applied to an electrically operated and controlled stokermechanism, it is obvious that the heat motor may be similarly op eratedby remote control devices other than a room thermostat and the openingand closing of tial alignment with the flxed ends, a movable electricheater arranged between the coils mounted to heat alternately therespective coils, a floating transmission link, means connecting thefloating link to the free ends 01 the coils to cause the said ends toact in unison in reciprocating the link as one coil is heating and theother is cooling, means to reciprocate the electrical heater between thecoils, and means carried by the floating link to actuate the heaterreciprocating means at each reciprocation oi the floating link.

2. The structure of claim 1 including a motor shaft, and meansinterposed between the floating link and shaft to impart a rotativemovement thereto upon reciprocation of the link.

3. The structure of claim 1 wherein the means to reciprocate theelectrical. heater includes means for adjusting the operativerelationship between the reciprocating means and actuating meanstherefore carried by the floating link, to control the duration of theperiods for applying heat to saidcoils.

4. The structure 01 claim 1 wherein the me to reciprocate the electricalheater includes a support for said heater mounted for oscillation andprovided with an adjustable heater oscillator, and said floating linkmounting a heater actuator coacting therewith to control the periodsduring which heat is applied to said coils.

5. The structure of claim 1 including a motor shaft and means interposedbetween the floating link and shaft to impart rotative movement theretoupon reciprocation of the link, said means comprising a ratchet wheelsecured to the shaft with oppositely disposed pawls arranged toreciprocate in unison thereover, a reciprocating cradle mounting saidpawls, and a sliding operating connection between the cradle andfloating link to reciprocate said cradle, whereby the oscillation of thecradle in one direction causes one of the pawls to impart a rotation tothe ratchet wheel while the other pawls travels over the teeth thereofand upon reverse movement the second pawl imparts a continuation or therotative movement to the other ratchet wheel while the flrst pawltravels over the teeth thereof.

IRA E. McCABE.

